Skin Bumps after Itching. Or stomach?

I'm suffering from mosquito bite like skin bumps for last 5-6 months which appear randomly on any part of body after itching. The bumps are itchy in nature and remain on body for some time. When itchiness is over, they disappear. They appear while sleeping which hampers my sleep also. In addition to this, I have problem of heart burn and GERD reflux like feeling also. The strange thing is that when I took some medication from medical store for itching, I got some relief from heart burn and GERD. Similarly few days back, when I took cough syrup for cough, I got temporary relief from bumps and itchiness. After going through some sites, I came to know that fungal infection can cause swelling in food pipe. Now I'm confused which doctor I should contact, Dermatologist or Gastroenterologist? As I'm not sure what is the root cause of problem. What tests are required to confirm the actual problem? Can Dermatologist treat the fungal infection if its in food pipe or stomach? Pls HELP & SUGGEST.